sanding moulding trims

[mreza Salav]

What would you recommend for sanding moulding trims (not by hand, hundreds of linear foot)?
A molding sander kit from Stockroomsupply?
Mac mop from klingspor on a shaper (or something similar)?
Some other "flap wheel" like the ones here: http://www.woodworkingshop.com/specialty-abrasives/

[mreza Salav]

There gotta be some people who have experience with some of these, please...

[Jamie Buxton]

The answer may depend on the profile of the molding. Sanding a simple cove molding would be different from sanding egg and dart.


You might also consider the Festool LS130EQ. Porter Cable had a similar sander, but I don't think it is still available.

[Mark Bolton]

This sort of question may get a bit more answers on more of a production forum (no offense to SC). Even a quick search (likely have?).

[glenn bradley]

Showing the profile will yield more and better answers. There are too many different profiles for one method to be adequate. I use sanding mops for gentle curves and astrals but, they would not be the answer foe dentil molding. Any profile with a sharp edge will suffer under a mop of too high a grit. Your acceptable loss of clarity will also be a factor.

[Jeff Duncan]

I agree with Glenn that any of the flap wheels or mop sanders are going to be problematic for moldings with sharp details. There are sanders for molding out there....though they run many thousands of dollars!

FWIW when I worked in a 30 man shop we sanded it all by hand. I'm not talking hundreds of feet.....but thousands!!! I remember one job sanding a couple thousand lineal feet of maple crown....4 of us doing it took a couple days IIRC.......sometimes there's just no easy way to do it:o

good luck,
JeffD

[peter gagliardi]

I own a small production shop. We make at least 1000's if not 10's of thousands of linear feet of molding per year. We sand it ALL by hand! If your machine is putting out a nice clean finish it only takes a couple minutes to break the knife glaze off.
Typically we are using Rhinosoft paper at 180 grit, and finish at 220 or 320 depending on how close or far away it is from a normal persons sight line it is . We tried various machines and flap sanders - not at all happy with results. They have a tendency to introduce their own " form" of mill marks, and they de-crispify, or round all the nice sharp edges that are the hallmark of custom molding. We regularly have runs of a few hundred to 5 hundred feet of molding- a couple hours and done. The trick is to pay attention to the wear rate of your paper, and boil it down to how many strokes on a given length of board are needed to break the glaze- usually under 10. So you do an arms length to ten, advance board, repeat, etc...
Really not hard- boring yes, but not hard. Don't be afraid, it's only a little work.
Peter

[Peter Quinn]

Few around here have probably had the occasion to sand a house full of trim on a production basis. I work for a place that makes custom trim on through molders, we don't sand anything. We do run slow feed rates and tight hold downs, so pad sanding with a sponge , maybe 150-220 is all that's neccessary. I something like a base molding we have sanded the broad flat surfaces on request, takes out a lot of the work. But I have no experience with machine set ups for sanding trim. You would need a slow spindle speed on a shaper, like 1500rpm. My minimax has a sanding speed, I've never tried it.

[mreza Salav]

By trim moulding I meant baseboards, casings, etc. Majority of the profiles aren't fixed/selected yet.
I have seen a crew of 4 sand thousands (over 6k I'm sure in one job) feet of moulding do the initial sanding and one before the final layer of finish in a few days.
So I guess it is most likely hand sanding for me too. I might try a couple of these wheels to see how it goes.

For hand sanding, I've read some suggest make a mold of the profile (using for e.g. bondo) and then attache abrasives to it (sounds tricky especially that you have to change the paper frequently). My feeling is a soft pad (like Rynosoft) would do a better job, am I right?

[Mark Bolton]

The block mold with paper has the same issues as have been mentioned, if your trim has sharp points, which you will want to remain crisp, it will be impossible to attach the paper and hand-operate the block in a way that doesn't soften those sharp edges. Like above, the key is if your making your trim to run the material as clean as possible to make hand sanding minimal.

[Peter Quinn]

I use these, or something very much like these available from a number of manufacturers.

http://www.woodworkingshop.com/product/fa02805/

http://www.woodworkingshop.com/product/fa03442/

The first is good for basic profiles and broad curves, the second "ultra flex" works well for more intricate profiles that might get changed or dulled by the slightly denser pads. The flat parts such as on door jambs or base molding gets the wide belt and ROS to as much as is possible. If you are making any trim on a shaper it can be helpful to sand flat edges if any exist (such as back bands) before milling to minimize hand sanding later. Or, a popular saying among cabinet makers is "well, lets let the painter take care of that!"

[Mel Fulks]

Never worked anywhere that sanded all of the mouldings. I agree with the point made earlier about knowing what profiles you are concerned with. For instance,base trim with a beaded edge can be just run through a widebelt if the knife was ground so that the bead is lower and wont be flattened . A few times I have been asked to repair hundreds of feet of sander flattened bead .I always decline that honor and reccommend that the incompetant who ruined it fix it. If you are using steel knives of the lowest cost you are doing more sanding than you would with a good steel. The idea that the cheap knives are just as good for "short runs" is widely circulated foolishness. Generally even on stain grade work our mouldings have not been sanded except ,of course ,at the mitres etc.when installed. The slickest mouldings I ever saw were run on the old square head moulders ,almost every species was actually shiny.

[Rick Fisher]

For sanding a volume of moulding .. on a somewhat regular basis. I would look at a brush sander ..

If you had the space for a stationary machine, and the volume, it would be a money maker ..

[mreza Salav]

Thanks for the comments. It's not a production shop, it's a hobby shop (mine) who will be busy with a "one time only" stuff for the house we are building.

[Mark Bolton]

Thanks for the comments. It's not a production shop, it's a hobby shop (mine) who will be busy with a "one time only" stuff for the house we are building.

For that I would put my efforts into getting as clean a profile as possible off your equipment and deal with a few licks with paper/sponge backed, block, whichever you choose. The sanding of course sucks but its really not that bad.

Do a search on YouTube for sanding molding. I watched a few mop sanders on there a long time ago. If your trim is hardwood you may be able to put somethjng together but on sharp profiles it wouldn't work for me.